drm/dp: move intel_dp_vsc_sdp_pack() to generic helper

intel_dp_vsc_sdp_pack() can be re-used by other DRM drivers as well.
Lets move this to drm_dp_helper to achieve this.

changes in v2:
	- rebased on top of drm-tip
Acked-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240220195348.1270854-1-quic_abhinavk@quicinc.com

drivers/gpu/drm/display/drm_dp_helper.c

@@ -2913,6 +2913,84 @@ void drm_dp_vsc_sdp_log(struct drm_printer *p, const struct drm_dp_vsc_sdp *vsc)
 }
 EXPORT_SYMBOL(drm_dp_vsc_sdp_log);
 
+/**
+ * drm_dp_vsc_sdp_pack() - pack a given vsc sdp into generic dp_sdp
+ * @vsc: vsc sdp initialized according to its purpose as defined in
+ *       table 2-118 - table 2-120 in DP 1.4a specification
+ * @sdp: valid handle to the generic dp_sdp which will be packed
+ * @size: valid size of the passed sdp handle
+ *
+ * Returns length of sdp on success and error code on failure
+ */
+ssize_t drm_dp_vsc_sdp_pack(const struct drm_dp_vsc_sdp *vsc,
+			    struct dp_sdp *sdp, size_t size)
+{
+	size_t length = sizeof(struct dp_sdp);
+
+	if (size < length)
+		return -ENOSPC;
+
+	memset(sdp, 0, size);
+
+	/*
+	 * Prepare VSC Header for SU as per DP 1.4a spec, Table 2-119
+	 * VSC SDP Header Bytes
+	 */
+	sdp->sdp_header.HB0 = 0; /* Secondary-Data Packet ID = 0 */
+	sdp->sdp_header.HB1 = vsc->sdp_type; /* Secondary-data Packet Type */
+	sdp->sdp_header.HB2 = vsc->revision; /* Revision Number */
+	sdp->sdp_header.HB3 = vsc->length; /* Number of Valid Data Bytes */
+
+	if (vsc->revision == 0x6) {
+		sdp->db[0] = 1;
+		sdp->db[3] = 1;
+	}
+
+	/*
+	 * Revision 0x5 and revision 0x7 supports Pixel Encoding/Colorimetry
+	 * Format as per DP 1.4a spec and DP 2.0 respectively.
+	 */
+	if (!(vsc->revision == 0x5 || vsc->revision == 0x7))
+		goto out;
+
+	/* VSC SDP Payload for DB16 through DB18 */
+	/* Pixel Encoding and Colorimetry Formats  */
+	sdp->db[16] = (vsc->pixelformat & 0xf) << 4; /* DB16[7:4] */
+	sdp->db[16] |= vsc->colorimetry & 0xf; /* DB16[3:0] */
+
+	switch (vsc->bpc) {
+	case 6:
+		/* 6bpc: 0x0 */
+		break;
+	case 8:
+		sdp->db[17] = 0x1; /* DB17[3:0] */
+		break;
+	case 10:
+		sdp->db[17] = 0x2;
+		break;
+	case 12:
+		sdp->db[17] = 0x3;
+		break;
+	case 16:
+		sdp->db[17] = 0x4;
+		break;
+	default:
+		WARN(1, "Missing case %d\n", vsc->bpc);
+		return -EINVAL;
+	}
+
+	/* Dynamic Range and Component Bit Depth */
+	if (vsc->dynamic_range == DP_DYNAMIC_RANGE_CTA)
+		sdp->db[17] |= 0x80;  /* DB17[7] */
+
+	/* Content Type */
+	sdp->db[18] = vsc->content_type & 0x7;
+
+out:
+	return length;
+}
+EXPORT_SYMBOL(drm_dp_vsc_sdp_pack);
+
 /**
  * drm_dp_get_pcon_max_frl_bw() - maximum frl supported by PCON
  * @dpcd: DisplayPort configuration data

drivers/gpu/drm/i915/display/intel_dp.c

@@ -4110,73 +4110,6 @@ intel_dp_needs_vsc_sdp(const struct intel_crtc_state *crtc_state,
 	return false;
 }
 
-static ssize_t intel_dp_vsc_sdp_pack(const struct drm_dp_vsc_sdp *vsc,
-				     struct dp_sdp *sdp, size_t size)
-{
-	size_t length = sizeof(struct dp_sdp);
-
-	if (size < length)
-		return -ENOSPC;
-
-	memset(sdp, 0, size);
-
-	/*
-	 * Prepare VSC Header for SU as per DP 1.4a spec, Table 2-119
-	 * VSC SDP Header Bytes
-	 */
-	sdp->sdp_header.HB0 = 0; /* Secondary-Data Packet ID = 0 */
-	sdp->sdp_header.HB1 = vsc->sdp_type; /* Secondary-data Packet Type */
-	sdp->sdp_header.HB2 = vsc->revision; /* Revision Number */
-	sdp->sdp_header.HB3 = vsc->length; /* Number of Valid Data Bytes */
-
-	if (vsc->revision == 0x6) {
-		sdp->db[0] = 1;
-		sdp->db[3] = 1;
-	}
-
-	/*
-	 * Revision 0x5 and revision 0x7 supports Pixel Encoding/Colorimetry
-	 * Format as per DP 1.4a spec and DP 2.0 respectively.
-	 */
-	if (!(vsc->revision == 0x5 || vsc->revision == 0x7))
-		goto out;
-
-	/* VSC SDP Payload for DB16 through DB18 */
-	/* Pixel Encoding and Colorimetry Formats  */
-	sdp->db[16] = (vsc->pixelformat & 0xf) << 4; /* DB16[7:4] */
-	sdp->db[16] |= vsc->colorimetry & 0xf; /* DB16[3:0] */
-
-	switch (vsc->bpc) {
-	case 6:
-		/* 6bpc: 0x0 */
-		break;
-	case 8:
-		sdp->db[17] = 0x1; /* DB17[3:0] */
-		break;
-	case 10:
-		sdp->db[17] = 0x2;
-		break;
-	case 12:
-		sdp->db[17] = 0x3;
-		break;
-	case 16:
-		sdp->db[17] = 0x4;
-		break;
-	default:
-		MISSING_CASE(vsc->bpc);
-		break;
-	}
-	/* Dynamic Range and Component Bit Depth */
-	if (vsc->dynamic_range == DP_DYNAMIC_RANGE_CTA)
-		sdp->db[17] |= 0x80;  /* DB17[7] */
-
-	/* Content Type */
-	sdp->db[18] = vsc->content_type & 0x7;
-
-out:
-	return length;
-}
-
 static ssize_t
 intel_dp_hdr_metadata_infoframe_sdp_pack(struct drm_i915_private *i915,
 					 const struct hdmi_drm_infoframe *drm_infoframe,
@@ -4269,8 +4202,8 @@ static void intel_write_dp_sdp(struct intel_encoder *encoder,
 
 	switch (type) {
 	case DP_SDP_VSC:
-		len = intel_dp_vsc_sdp_pack(&crtc_state->infoframes.vsc, &sdp,
-					    sizeof(sdp));
+		len = drm_dp_vsc_sdp_pack(&crtc_state->infoframes.vsc, &sdp,
+					  sizeof(sdp));
 		break;
 	case HDMI_PACKET_TYPE_GAMUT_METADATA:
 		len = intel_dp_hdr_metadata_infoframe_sdp_pack(dev_priv,

include/drm/display/drm_dp_helper.h

@@ -812,4 +812,7 @@ int drm_dp_bw_overhead(int lane_count, int hactive,
 		       int bpp_x16, unsigned long flags);
 int drm_dp_bw_channel_coding_efficiency(bool is_uhbr);
 
+ssize_t drm_dp_vsc_sdp_pack(const struct drm_dp_vsc_sdp *vsc,
+			    struct dp_sdp *sdp, size_t size);
+
 #endif /* _DRM_DP_HELPER_H_ */